Evaluation of the bending fatigue performance (stress to life relationship) of different gear materials subject to various manufacturing processes and why subsequent post processing treatments are of significance to gear and transmission designers.

To achieve the requested quality, most gears today are ground. The usual grinding process includes treating the gear flank but disengaging before reaching the root rounding area. If the gear is premanufactured with a tool without protuberance, then at the position where the grinding tool retracts from the flank a grinding notch in the tooth root area is produced. Such a notch may increase the bending stresses in the root area, thus reducing the strength rating.

The effect of load speed on straight and involute tooth forms is studied using several finite-element models.